Oh, and a note on the detailing: the little boxes labeled "COMM" are field telephones to communicate with the tank crew in the even of nuclear attacks blasting the radios off of it. Each box also has its own short-range radio as a backup to the tank's primary radios.

Coilguns spring to mind. Or maybe some super-sized electrolaser. Or just a bigass laser.

Baltar: "I don't want to miss a moment of the last Battlestar's destruction!"
Centurion: "Sir, I really think you should look at the other Battlestar."
Baltar: "What are you babbling about other...it's impossible!"
Centurion: "No. It is a Battlestar."

Corrax Entry 7:17: So you walk eternally through the shadow realms, standing against evil where all others falter. May your thirst for retribution never quench, may the blood on your sword never dry, and may we never need you again.

Coilguns indeed. It fires a ~300lb (136kg) 4" depleted uranium dart with a ferromagnetic sabot at up to Mach 5. From my last calculations (off the top of my head right now) it can recharge the main armament up to a full power shot in five seconds. All of the secondary weapons are also coilguns. The four little spheres on top are PD lasers.

Imperial528 wrote:Coilguns indeed. It fires a ~300lb (136kg) 4" depleted uranium dart with a ferromagnetic sabot at up to Mach 5. From my last calculations (off the top of my head right now) it can recharge the main armament up to a full power shot in five seconds. All of the secondary weapons are also coilguns. The four little spheres on top are PD lasers.

I feel like Picard and the unclear quantity of lights, but I only see three spheres up there... .

Given the sheer size of this beast, I think it could use possibly some varied ordinance for self-defense. I'm sure that the small coilguns, if they have sufficient traverse speed and elevation, can provide anti-aircraft cover.

Maybe a VLS mount on the back, either for rooting out entrenched enemies or, if you go with a larger and more sophisticated unit, even counter-battery against artillery pieces. I see artillery and aircraft being the biggest challenges - being that large limits your use of terrain and even where you put the tank in particularly rough areas. What's the armour/survivability package like?

Venator wrote:I feel like Picard and the unclear quantity of lights, but I only see three spheres up there... .

Given the sheer size of this beast, I think it could use possibly some varied ordinance for self-defense. I'm sure that the small coilguns, if they have sufficient traverse speed and elevation, can provide anti-aircraft cover.

Maybe a VLS mount on the back, either for rooting out entrenched enemies or, if you go with a larger and more sophisticated unit, even counter-battery against artillery pieces. I see artillery and aircraft being the biggest challenges - being that large limits your use of terrain and even where you put the tank in particularly rough areas. What's the armour/survivability package like?

The three large domes on the top are covers for orbital communications equipment.

The secondary armaments are 0.8x4"/20.32x101.6mm cannons that fire SAPHEI/HEFI mix, two per secondary turret and three mounted alongside the primary gun for anti-vehicle and anti-aircraft. The tertiary armament consists of 0.2x2"/5.1x50.8mm miniguns that fire a steel round with a depleted uranium penetrator core, primarily meant as anti-infantry, point defense, and for use against light vehicles and aircraft. Two per secondary turret, and two alongside the main gun. Dimensions given are the diameter and length of the projectiles; as coilguns the ammunition requires no propellant.

Hull side armor is 9"/228.6mm flat on the side-skirts, and 3"/76.2mm flat after the tracks.

I haven't quite gotten a detailed armor mockup of the turret, but it would likely be 12"/304.8mm front, 9"/228.6mm side, and 6"/152.4mm rear with 9"/228.6mm thick roof and 5"/127mm thick floor, though the turret floor would only be armored in areas that don't consistently overlap with the hull deck.

As for frontal PD, the existing turret should handle well enough, and I'd rather not mount anything onto the glacis if possible to avoid compromising the armor. As it is the forward turret and driver's sensor suite are mounted into a bulkhead to preserve armor integrity. I could look into it though, might just smack one onto the front of the driver's suite.

Oh, and fun fact: the tank has 28 roadwheels, though it should be able to function well enough with up to half of them compromised.

And as it seems I didn't mention it earlier, it has slightly less ground pressure than an elephant, at 34.5 PSI. Which I don't think is too bad all things considered.

34.5psi would make the vehicle completely unusable on soft ground. That's the ground pressure of a typical passenger car. Anything over 25psi is about doom off road, 15-16psi is where tanks try to be maximum. The Gernan Maus was at 20psi but could sort of get away with it because it was very slow, though the Germans never tested it that much either. I would suggest if you want to draw giant tanks not to think too hard about such things, it's just going to get you into trouble putting numbers on things.

The odds of driving a heavy tracked vehicle anywhere with even a single broken road wheel is slim to none, possible only at low speed. You'd just throw the track doing that which then becomes an incredibly huge problem on this scale. Lots of road wheels side by side are troublesome. Lots of road wheels lengthwise is good though, you should really have more smaller ones. This would even out the ground pressure and make the tank more mobile off road. On road it will be slower, but that's not a prime concern.

As for the armor, what do you envision the armor being? Some kind of sci fi material? Because for something like a modern armor package you'd need far greater actual volume for said armor then you are estimating, though I figure you have plenty of volume to play with. If plain steel, then well, that's pretty hopeless since you would need a solid meter of it just to cope with 120mm tank fire. The driver compartment is also kind of hopeless but whatever. For reference the armor on the front of an M1 tank turret is a 50in thick volume.

Your main gun BTW would have about 200 MJ of muzzle energy, which is about two thirds that of a 16in naval gun. This vehicle would probably be able to handle that but it'd be reallly violent. You should really think about adding some kind of high caliber coaxial weapon in the 50-100mm range simply because targets will exist you do not want to fire 300lb of DU at. If you want to be unusual I'd suggest replacing one of those 20mm cannon mounts with a ~75mm grenade launcher coupla that can also fire at high angles like a mortar. Give it air burst rounds so it can clean out infantry in hard to reach places ect.. fire it near friendly troops and the like, also it would be big enough to fire smoke rounds. Huge tanks suffer from huge amounts of dead space, some kind of vertical firing weapon can help improve that situation as on the Israeli Merkava.

"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956

I'll look into making the tracks wider. I may be able to get away with narrowing the hull compartment to make room, to avoid widening it.

As for the armor, I was thinking a future version of composite armor. That being said, for the turret armor 50" is easily doable, and I could probably increase the frontal hull armor easily enough, possibly to twice as thick. For the first armor mock-up I deliberately low-balled because I frankly have no idea what the internals will look like outside of the crew compartment and reactor mock-ups I made. As it is, there is plenty of room for additional armoring in the front of the tank and the turret, though the turret armor is more flexible in this design since the crew compartment is entirely within the hull.

The driver's actual seat is a good 12' behind the front of the tank, the part protruding from the upper glacis is a sensor suite, though it includes periscopes for backups. Said periscopes naturally take a few bends around armor plating and include armor glass bulkheads so that a proximity explosion or contact explosion on the front of the tank can't easily be funneled into the crew compartment. There would additionally be protective shutters over and inside the periscopes that would be closed when they weren't in use (i.e. when the cameras are still functioning). The gunner's optics and commander's optics have similar setups.

I'll see what I can do about adding midrange caliber weapons. I had originally wanted to avoid them, but from what you've said, they seem more reasonable.